<!--
 * @FileDescription: vue的根组件，用于存放某些关键函数
 * @Author: 叶永鸿
 * @Date: 2021-7-17
 * @LastEditors: 叶永鸿
 * @LastEditTime: 2021-7-18
 -->
<template>
  <div id="app">
    <router-view />
  </div>
</template>
<script>
export default {
  name: "App",
  created() {
    //在页面加载时读取sessionStorage里的状态信息

    if (sessionStorage.getItem("store")) {
      this.$store.replaceState(
        Object.assign(
          {},
          this.$store.state,
          JSON.parse(sessionStorage.getItem("store"))
        )
      );
    } 

    //在页面刷新时将vuex里的信息保存到sessionStorage里
    window.addEventListener("beforeunload", () => {
      sessionStorage.setItem("store", JSON.stringify(this.$store.state));
    });
  },
};
</script>

<style>
body,
html,
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  height: 100%;
  width: 100%;
}
</style>
